Self-locking nut.



E. E. MAHER.

SELF LOCKING NUT.

APPLICATION FILED SEPT. 9, 1912.

1,81,54Q Patented Dec. 16, 1913.

2 SHEETS-SHEET l.

E. E. MAHER.

SELF LOCKING NUT.

APPLICATION FILED smme, 1912.

LQ8LMU. Patented Dec. 16,1913.

2 SHEET S-SHEET 2.

EUGENE E. MAHER, OF CHICAGO, ILLINOIS, ASSIGNOR. TO K NUT 00., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SELF-LOCKING NUT.

Specification of Letters Patent. I Patented Dec. 1-6, $913.

Application filed September 9, 1912. Serial No. 719,486.

To all whom it may concern Be it known that I, EUGENE E. MAHER, a citizen of the United States, and a resident of Chicago, Cook county, Illinois, have invented certain new and useful Improvements in Self-Locking Nuts, of which the following is a specification.

My invention relates to nut and bolt locks and has particular reference to means for. locking threaded nuts upon and with threaded members such as bolts.

The object of my invention is to provide a one-piece nut which shall carry within itself all of the elements necessary for securely and firmly looking it upon a suitably threaded bolt; which can be manufactured at low cost; which shall develop a maximum holding power and can be applied as easily as a non-locking nut, but once properly applied will be automatically locked against any but intentional rotation upon the bolt even independent of the load surface against which is was applied.

Another object of my invention is to provide a self locking nut of such form, that the standard dimensions for nuts may be followed out for all the various sizes, and of such form that it can be made in substantially the same ways, and with substantially the same machinery as is now used to produce standard commercial nuts of various kinds.

My invention will be more readily understood by reference to the accompanying drawings which illustrate the preferred embodiment thereof, and in which:

Figure 1 is a perspective view looking at the load or bearing surface of a self locking nut embodying my invention; Fig. 2 is a cross section through the nut after the bolt hole is formed, but before the locking portion is formed; Fig. 3 is a cross sectional view showing the nut after the locking portion has been formed; Fig. 4 is a View similar to Fig. 3, but showing the bolt hole threaded; Fig. 5 is a sectional detail showing the nut locked in position on a bolt, against a load surface; Fig. 6 illustrates a modified form of my invention wherein the locking portion is circular in form; and Fig. 7 is a cross section on line 11-11 thereof; Figs. 8 and 9 are respectively perspec tive and cross sectional views showing asquare nut shown in the drawings, but in all cases where I refer to or show a s uare n'ut, I wish it to beunderstood that plate. making hexagonal, octagonal and polygonal nuts of various types. I have not illustrated these near modifications, since it is obvious that the operation and functions of the nut would be in no wise altered by mere external conformation thereof. A square nut is usually made from a long bar of metal of the thickness desired in the nut' andof a width equal to one side. Pieces are sheared from such a bar and bolt'holes are punched therein. Now referring particularly to Figs. 1 to 5 which illustrate a very desirable form of my invention,1 (Fig. 2) represents the nut body after it has been severed from a bar and punched to form the bolt hole 2. In these operations a crown 3 is formed which through long usage has come to indicate to a mechanic that this is the top or non-bearing surface of the nut. I prefer therefore, to retain this well known characteristic in my nut as a'guide to the user. I next form from the nut body wings which flare upwardly therefrom. This may be done by cutting into the nut along the dotted lines 44 (Fig. 2) with wedge shaped knives that enter the bolt hole, and which when retracted leave wedge-like recesses 5,5, intwo of the opposite sides of the nut. It will be seen that the wings are only slightly spaced from the body adjacent the bolt hole as indicated at 5, 5. In this manner wing members 6, 6, are struck up without removing metal forming aconcave outer face 7 which shall be referred to herein as the nu-t bearing surface, and two curved inner surfaces, 7, 7. Since the wing members 6, 6, are formed without removing metal they can berestored for purpose of locking the nut in place as will be more fully described hereinafter, to substantially the same position they occupieclbecontem- 6, 6, which I shall herein term the lockingwings are formed Fig. 3), the nut is threaded through as s own in Fig. 4 from face to face. It will be seen that the outer faces 6, 6 of the locking wings are set in or angularly disposed to the faces 1, 1

of the nut body. The nut is put on the bolt nut bearing surface first, and it starts on with a finger lit, wrench'fit, or such other fit as may be desired, just like an ordinary nut. The outer edges 6 of the locking wings first contact the load surface 8, thus giving a long leverage first where most needed, and then successively other portions of the locking wings approaching the center. In this manner as the nut 1s screwed on, the wings are replaced or restored to sub? stantially the same position that the metal thereof occupied before the wings were formed. The restored or reformed position is indicated in Fig. 5. The action is practically the converse of that of forming. It

will there be noted that the outer faces 6,

6, of the locking wings are restored to the plane of the nut body faces and that the nut is substantially a solid standard nut in form, appearance and strength and while my nut may have been originally tapped to go on easy like an ordinary nut, it now differs from the ordinary nut in that it is now firmly locked in place upon the bolt 9 against movement in either direction.

The locking action of my nut is substan tially as follows: As the locking wings "are brought into contact with the load surface, and the nut is forced forward, they are depressed in the direction of the arrows (Fig. 4). Since the cut 5 made in formin the wings enters the bolt hole, the threads 10 of the locking wings are in a sense mounted as on a 'lever, the fulcrum of which is adjacent the innermost portion 5 of the cut 5. The threads 10 of the nut locking portion are thereb brought down into more intimate, forcefu frictional con-.

tact with the contiguous bolt threads. When a nut is screwed upon -a bolt or other threaded member, the forward or advance faces of the nut threads are in frictional engagement with the forward faces of the bolt thread while the rear faces of the nut threads lag slightly behind the rear faces of the bolt thread, or in other words are slightly spaced therefrom. This isespecially true in the ordinary commercial nut whichis made cheaply in large quantities,

and is usually a loose fit and is augmented when the nut is 'brought against the load surface. In this position the nut may be said to be leaning away from the load, 2'. c. it is pushed back against the bolt thread faces nearestto the load surface. My nut acts to lock it in this position by movement of the locking wings whereby the locking wing threads are brought into greater frictional contact with the contiguous bolt threads. When the nut is screwed home so that the wings are restored to thepositions they occupied before being out, they slightly 'distort the contacting bolt threads. This result constitutes another means of locking the nut in place. My nut is further frictionally held upon the bolt by what I term elliptical engagement. As the nut is screwed home and the wings are restored or depressed, the nut bolt hole of the locking portion is slightly distorted from a true circle to that of a slight ellipse. This causes two sides of the locking portion of the nut to move inwardly at this point so that the nut threads on these two sides frictiona'lly engage the base and sides of the bolt threads with great pressure which constitutes another action. Another locking action which I secure in my nut is that caused by frictional engagement of the nut bearing surface with the load surface 8. This frictional engagement acts in conjunction with the other forces to prevent accidental rotation of the nut upon the bolt. The locking actions described are ample to hold the nut against any unintentional movement on the bolt un-- der all circumstances, but of course the nut can be removed when desired by using an ordinary wrench. Nuts of this kind are much used in securing rails together and in other places where there is considerable vibration. From the vibration and other causes the load surface often recedes slightly from the nut. nut has a tremendous advantage over many locking nuts which depend upon engagement with the load surface entirely for their lockin action. A notable instance of this Under such conditions my. i

is in t e case of locking nuts having spring members which engage the load surface and are held back thereby to produce the'locking action. In such nuts when the load surface recedes therefrom, the spring opens up and thus destroys the locking action. With my nut, however, even when the load surface recedes, while the locking wings spring back slightly, in no event do they spring far enough to destroy entirely the other three locking actions before described, namely, the increased thread frictional engagement caused by restoring the locking wings to their original positions, the elliptical engagement, due to moving of the sides inwardly, and the distorted thread hold, which the nut immovableuon the bolt. the load surface rece e from the nut as it sometimes does, the nut can then be screwed up to restore it to its complete locking efliciency.

To facilitate description and understanding of the modified forms of my invention shown *in Figs. 6- to 9, the same reference numerals used with reference to Figs. 1 to 5 are used to indicate like parts, and, I deem it unnecessary to describe the same in detail in view of the complete description of Figs. 1 t0 5.

It is sometimes desirable to prevent any possiblescoring of the home or load surface and in Figs. 6 and 7, I have illustrated a modified form of my invention particularly adapted for this purpose. I have herein made the locking portion circular in form, While the body portion of the nut may be square or of, such other polygonal form desired. I also round the edges 6 slightly and thus provide a locking nut devoid of sharp corners or edges. This nut can thus be screwed home with little danger of scoring or defacing the home surface. The rounded corners and edges also facilitate the seating of the nut. In using my nut for some purposes I prefer to have that form shown in Figs. 1 to 5 modified, however, to

the extent of slightly rounding either the edges 6 and corners 6, or both slightly, in order that the dragging friction on the home surface can be somewhat reduced. This form of my invention is shown in Figs.

8 and 9.

' metal and the nut is threaded from face to face. Then by a restitution of the wings the tional movement onthe bolt.

My nut is superior to an ordinary nut followed by an auxiliary locking nut because my nut contains less metal than an ordinary nut plus an auxiliary lock nut. Further an auxiliary locking nut, following a home nut, tends to shove it forward against the load and thereby diminishes the load bearing power of the home nut, while my nut does not take the load from any of its threads, because when locked on the bolt it is in normal position, that is, it is leaning away from the load.

It should be obvious from the foregoing description that the object and purposesof my invention are fully attained in the embodiment of same herein disclosed and that 'the disadvantages and defici'ences of locking nuts hitherto devised areremedied.

Should Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. As an article of manufacture, a selflocking nut of substantially standard nut dimensions, comprising a nut body portion and a nut locking portion integral therewith, said nut having a bolt hole, the said looking portion comprising two lockingwings flaring away from the body portion and formed substantially without removal of metal by transverse cuts which enter the bolt hole from two opposite nut faces, the

locking wings when brought into contact surface, the walls of the wings and adjacent body of the nut being substantially tangential at the juncture of the wings with they body portion.

3. The herein described locking nut comprising a body portion and a nut locking portion, the nut locking ortion comprising two wings of nut side lengt and being formed by transverse cuts which enter two opposite sides of the nut perpendicular to the vertical axis of the bolt hole, said wings being flared away from the body portion to form a substantially concave load surface, the walls of the wings and adjacent body of the nut being substantially tangential at the juncture of the wings with the body portion.

4. A self-locking nut of substantially standard nut dimensions comprising a body portion and an integral locking portion, said locking portion comprising two oppositely flared wing members, the walls of the wing members and the adjacent body of the nut being substantially tangential at the juncture of the wings with the body portion, said bolt hole being threaded, and the wing members being adapted to be brought into substantially full engagement with the body portion for the purpose of locking the nut upon the bolt.

5. In a self-locking nut, the combination of a nut body portion with a nut locking portion, the nut body and locking portion being provided with a bolt hole, the nut locking portion comprising two locking wings flaring away from the nut body portion' and displaced by a cutting tool entering transversely from opposed nut faces to points within the bolt hole, said wing "portions having outer faces slightly removed from the plane of the nut body faces, said bolt hole being threaded after the formation of the locking wings and the locking wings being adapted for restitution by engagement with the load surface, thereby i assuming substantially the same planes as the side faces of the body portion and forming therewith a wrench fit throughout substantially the thickness of the nut.

EUGENE E. MAHER.

Witnesses R. S. MCCREADIE, J OHIYR. LEFEVRE. 

